The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform
Miguel Valcarcel - One of the best experts on this subject based on the ideXlab platform.
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Continuous AutoAnalyzer for the evaluation of the exhaustion of industrial degreasing baths based on the determination of total grease and surfactant contents
Journal of Chromatography A, 2005Co-Authors: Eva Aguilera-herrador, Rafael Lucena, Soledad Cardenas, Miguel ValcarcelAbstract:A continuous flow AutoAnalyzer for at-line monitoring of total grease and surfactant contents in alkaline degreasing baths is proposed. For this purpose, a simple, robust, automated configuration has been on-line coupled to an universal response detector, such as the evaporative light scattering one. The proposed AutoAnalyzer constitutes an advantageous alternative to manual procedures and achieves the determination of both indices in ca. 15 min. The parameters thus obtained can be used to evaluate the degree of exhaustion of the bath as therefore allows the timely decision-making about reusability, maintenance or renewal. The fractionation model has been validated using attenuated total reflection-Fourier transform-infrared (ATR-FT-IR) spectroscopy. The potential of the method was realized by applying it to the analysis of 15 real samples obtained from precleaning and cleaning alkaline baths from a production line of a metal industry.
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AutoAnalyzer for continuous fractionation and quantitation of the polyphenols content in wines
Journal of Chromatography A, 2005Co-Authors: Rafael Lucena, Soledad Cardenas, Mercedes Gallego, Miguel ValcarcelAbstract:Abstract A simple continuous flow AutoAnalyzer for the on-line fractionation of the polyphenols content in wines is proposed. The target compounds are isolated from the matrix by solid-phase extraction on an RP-C 18 sorbent column, using selective solvents for the sequential elution of each polyphenol family. Moreover, evaporative light scattering detection (ELSD) is used for the first time for the on-line monitorization of the three polyphenol fractions present in the wine samples. Thus, a single sample injection is required to determine the global concentration of the three selected polyphenol fractions and the whole analysis is completed within a few minutes. Three calibration graphs were constructed for quantitative analysis of the global compounds concentration in every fraction and covered the range 5–300 mg l −1 (expressed as gallic acid). Average repeatability, expressed as relative standard deviation, was 4%. The proposed autonalyzer was applied to the analysis of a variety of commercial wine samples. The results obtained were compared with those provided by the Folin–Ciocalteau method, being similar in all instances.
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Continuous flow AutoAnalyzer for the sequential determination of total sugars, colorant and caffeine contents in soft drinks
Analytica Chimica Acta, 2005Co-Authors: Rafael Lucena, Soledad Cardenas, Mercedes Gallego, Miguel ValcarcelAbstract:Abstract A novel AutoAnalyzer for sequential determination of total sugars, class IV caramel and caffeine contents in soft drinks is described for the first time. The multiparametric AutoAnalyzer is based on the on-line coupling of a continuous solid-phase extraction unit with two detectors in series: UV–vis and evaporative light scattering (ELSD) detectors. Caffeine is selectively retained on the sorbent column and the other components are sequentially determined in the effluent. Caffeine was further eluted with an acetonitrile stream and the signal registered in the ELSD. The proposed AutoAnalyzer is a useful tool for the determination of these macrocomponents in the selected matrices on account of the high level of capital, basic and productivity-related analytical properties it provides. The method was validated through the use of spiked samples and applied to the analysis of more than 20 different soft drink samples (regular, diet, caffeine-free, energy drinks) with satisfactory results.
Rafael Lucena - One of the best experts on this subject based on the ideXlab platform.
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Continuous AutoAnalyzer for the evaluation of the exhaustion of industrial degreasing baths based on the determination of total grease and surfactant contents
Journal of Chromatography A, 2005Co-Authors: Eva Aguilera-herrador, Rafael Lucena, Soledad Cardenas, Miguel ValcarcelAbstract:A continuous flow AutoAnalyzer for at-line monitoring of total grease and surfactant contents in alkaline degreasing baths is proposed. For this purpose, a simple, robust, automated configuration has been on-line coupled to an universal response detector, such as the evaporative light scattering one. The proposed AutoAnalyzer constitutes an advantageous alternative to manual procedures and achieves the determination of both indices in ca. 15 min. The parameters thus obtained can be used to evaluate the degree of exhaustion of the bath as therefore allows the timely decision-making about reusability, maintenance or renewal. The fractionation model has been validated using attenuated total reflection-Fourier transform-infrared (ATR-FT-IR) spectroscopy. The potential of the method was realized by applying it to the analysis of 15 real samples obtained from precleaning and cleaning alkaline baths from a production line of a metal industry.
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AutoAnalyzer for continuous fractionation and quantitation of the polyphenols content in wines
Journal of Chromatography A, 2005Co-Authors: Rafael Lucena, Soledad Cardenas, Mercedes Gallego, Miguel ValcarcelAbstract:Abstract A simple continuous flow AutoAnalyzer for the on-line fractionation of the polyphenols content in wines is proposed. The target compounds are isolated from the matrix by solid-phase extraction on an RP-C 18 sorbent column, using selective solvents for the sequential elution of each polyphenol family. Moreover, evaporative light scattering detection (ELSD) is used for the first time for the on-line monitorization of the three polyphenol fractions present in the wine samples. Thus, a single sample injection is required to determine the global concentration of the three selected polyphenol fractions and the whole analysis is completed within a few minutes. Three calibration graphs were constructed for quantitative analysis of the global compounds concentration in every fraction and covered the range 5–300 mg l −1 (expressed as gallic acid). Average repeatability, expressed as relative standard deviation, was 4%. The proposed autonalyzer was applied to the analysis of a variety of commercial wine samples. The results obtained were compared with those provided by the Folin–Ciocalteau method, being similar in all instances.
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Continuous flow AutoAnalyzer for the sequential determination of total sugars, colorant and caffeine contents in soft drinks
Analytica Chimica Acta, 2005Co-Authors: Rafael Lucena, Soledad Cardenas, Mercedes Gallego, Miguel ValcarcelAbstract:Abstract A novel AutoAnalyzer for sequential determination of total sugars, class IV caramel and caffeine contents in soft drinks is described for the first time. The multiparametric AutoAnalyzer is based on the on-line coupling of a continuous solid-phase extraction unit with two detectors in series: UV–vis and evaporative light scattering (ELSD) detectors. Caffeine is selectively retained on the sorbent column and the other components are sequentially determined in the effluent. Caffeine was further eluted with an acetonitrile stream and the signal registered in the ELSD. The proposed AutoAnalyzer is a useful tool for the determination of these macrocomponents in the selected matrices on account of the high level of capital, basic and productivity-related analytical properties it provides. The method was validated through the use of spiked samples and applied to the analysis of more than 20 different soft drink samples (regular, diet, caffeine-free, energy drinks) with satisfactory results.
S. Cozzi - One of the best experts on this subject based on the ideXlab platform.
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A new application of the diacetyl monoxime method to the automated determination of dissolved urea in seawater
Marine Biology, 2004Co-Authors: S. CozziAbstract:A new application of the diacetyl monoxime method for the determination of dissolved urea in seawater is presented, based on the Alpkem AutoAnalyzer (OI, Analytical). This system has several advantages over automated methods previously described in the literature. The urea cartridge can be easily built using nut/ferrule connections, and the external thermostatic bath is not required. The system is set up to operate at low urea concentrations (0–3 µM urea), but it is linear up to 100 µM urea. The sample volume needed for analysis is 0.4 ml, and the rate of analysis is 25 samples h^−1. The precision of analysis (CV) of seawater samples is 2.1% at 0.50 µM urea, and the detection limit is 0.02 µM urea. The interference on the colorimetric measurement due to formation of Brij-35 aggregate in strongly acidic media was eliminated by substituting this wetting agent with hexadecyl–trimethyl–ammonium bromide; thus, this method is suitable for other AutoAnalyzer technologies that use small-diameter transmission tubes and small-sized spectrophotometric flowcells.
Soledad Cardenas - One of the best experts on this subject based on the ideXlab platform.
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Continuous AutoAnalyzer for the evaluation of the exhaustion of industrial degreasing baths based on the determination of total grease and surfactant contents
Journal of Chromatography A, 2005Co-Authors: Eva Aguilera-herrador, Rafael Lucena, Soledad Cardenas, Miguel ValcarcelAbstract:A continuous flow AutoAnalyzer for at-line monitoring of total grease and surfactant contents in alkaline degreasing baths is proposed. For this purpose, a simple, robust, automated configuration has been on-line coupled to an universal response detector, such as the evaporative light scattering one. The proposed AutoAnalyzer constitutes an advantageous alternative to manual procedures and achieves the determination of both indices in ca. 15 min. The parameters thus obtained can be used to evaluate the degree of exhaustion of the bath as therefore allows the timely decision-making about reusability, maintenance or renewal. The fractionation model has been validated using attenuated total reflection-Fourier transform-infrared (ATR-FT-IR) spectroscopy. The potential of the method was realized by applying it to the analysis of 15 real samples obtained from precleaning and cleaning alkaline baths from a production line of a metal industry.
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AutoAnalyzer for continuous fractionation and quantitation of the polyphenols content in wines
Journal of Chromatography A, 2005Co-Authors: Rafael Lucena, Soledad Cardenas, Mercedes Gallego, Miguel ValcarcelAbstract:Abstract A simple continuous flow AutoAnalyzer for the on-line fractionation of the polyphenols content in wines is proposed. The target compounds are isolated from the matrix by solid-phase extraction on an RP-C 18 sorbent column, using selective solvents for the sequential elution of each polyphenol family. Moreover, evaporative light scattering detection (ELSD) is used for the first time for the on-line monitorization of the three polyphenol fractions present in the wine samples. Thus, a single sample injection is required to determine the global concentration of the three selected polyphenol fractions and the whole analysis is completed within a few minutes. Three calibration graphs were constructed for quantitative analysis of the global compounds concentration in every fraction and covered the range 5–300 mg l −1 (expressed as gallic acid). Average repeatability, expressed as relative standard deviation, was 4%. The proposed autonalyzer was applied to the analysis of a variety of commercial wine samples. The results obtained were compared with those provided by the Folin–Ciocalteau method, being similar in all instances.
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Continuous flow AutoAnalyzer for the sequential determination of total sugars, colorant and caffeine contents in soft drinks
Analytica Chimica Acta, 2005Co-Authors: Rafael Lucena, Soledad Cardenas, Mercedes Gallego, Miguel ValcarcelAbstract:Abstract A novel AutoAnalyzer for sequential determination of total sugars, class IV caramel and caffeine contents in soft drinks is described for the first time. The multiparametric AutoAnalyzer is based on the on-line coupling of a continuous solid-phase extraction unit with two detectors in series: UV–vis and evaporative light scattering (ELSD) detectors. Caffeine is selectively retained on the sorbent column and the other components are sequentially determined in the effluent. Caffeine was further eluted with an acetonitrile stream and the signal registered in the ELSD. The proposed AutoAnalyzer is a useful tool for the determination of these macrocomponents in the selected matrices on account of the high level of capital, basic and productivity-related analytical properties it provides. The method was validated through the use of spiked samples and applied to the analysis of more than 20 different soft drink samples (regular, diet, caffeine-free, energy drinks) with satisfactory results.
Jean Pierre Corriou - One of the best experts on this subject based on the ideXlab platform.
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An AutoAnalyzer for real-time detection of benzene and volatile organic compounds in paper mills
Environmental Chemistry Letters, 2020Co-Authors: Zhifeng Lin, Wenhao Shen, Tong Xin, Jean Pierre CorriouAbstract:Gas chromatography is commonly employed to detect gaseous pollutants. However, gaseous pollutants in paper mills are multicomponent and difficult to be detected and analyzed by gas chromatography. Therefore, we developed a novel AutoAnalyzer with an embedded supervisory system, with which multicomponent gaseous pollutants in paper mills can be detected in real time. The AutoAnalyzer was applied in two paper mills for the detections of the total volatile organic compounds (TVOC) and benzene at five sampling sites. The detection results show that the TVOC concentrations in two mills exceed the standard severely, especially in mill A, which can be attributed to the application of pulping and bleaching chemicals. In addition, benzene is also detected in Mill A due to benzene release from the fluorescent brighteners in the papermaking section. The large amounts of TVOC detected in the sequencing batch reactor (SBR) equalization tank of Mill A are explained by their release from the biodegradation of wastewater
